The objective of the proposed research is to define the mechanism of action of the important nutritional component vitamin A at the molecular level in organs other than the eye. Efforts will be made to purify to homogeneity and characterize two distinct specific cellular cytoplasmic binding proteins for retinol (vitamin A-alcohol) and for retinoic acid (vitamin A-acid) discovered recently by this laboratory to be present in a number of organs in all animal species examined and to delineate their role in cell metabolism. Emphasis is given to whether and how vitamin A, by interaction with these binding proteins, influences the nuclear transcriptional mechanism. The stimuli leading to the alterations of the levels of these binding proteins during perinatal developments of the rat will be explored. Special attention will be given to the influence of vitamin A deficiency of the mother on the contents of these proteins in the child. Nutritional and biochemical studies are emphasized.